History and Philosophy of Science
Eötvös University, Budapest 
Philosophy of Science Colloquium
Room 6.54 (6th floor) Monday 4:00 PM 
Pázmány P. sétány 1/A Budapest 
Phone/Fax: (361) 372 2924 
Location? 
19 April 4:00 PM 6th floor 6.54

Zoltán Gendler Szabó

The Sage School of Philosophy, Cornell University


Pronouns and variables
(Névmások és változók)

When
I teach introductory logic I tell my students that variables are sort
of like pronouns in natural languages and when I teach introductory
semantics I tell them that pronouns are sort of like variables
in the quantificational calculus. (Fortunately not many people take
both classes, so I have never been caught.) But pronouns and variables
are certainly not that similar: for one thing we usually have about a
dozen pronouns in a natural language but infinitely many variables in
the quantificational calculus. To match the expressive power of the
quantificational calculus, natural languages must have some devices of
treating different occurrences of the same pronouns as referring
to different things. The topic of my talk is how exactly natural
languages pull off the trick.

Comments & Discussion.
 István A. Aranyosi
 Zoltán Gendler Szabó


26 April 4:00 PM 6th floor 6.54

Gábor Etesi

Department of Geometry, Institute for Mathematics
Budapest University of Technology and Economics


Geometric computability theory and its relationship with the strong cosmic censor conjecture
(Geometriai kiszámíthatóságelmélet és kapcsolata az erős kozmikus cenzor hipotézissel)

In this lecture we
overview the recent progress in geometric computability theory by
enumerating those solutions to Einstein's equation which possess
gravitational computers capable to perform computations beyond the
Turing barrier. The class of such spacetimes is referred to as
MalamentHogarth spacetimes. Surprisingly, most of them are relevant
also from a physical viewpoint.
Then we point out a natural link between the strong cosmic censor
conjecture and MalamentHogarth spacetimes. Namely, (i) the conformal
class of an extendible maximal globally hyperbolic spacetime contains
a MalamentHogarth spacetime and (ii) for a MalamentHogarth
spacetime the GerochHorowitzPenrose formulation of the strong
cosmic censor conjecture is valid. These together imply a quite weak
version of the strong cosmic censor conjecture.
Finally we argue that albeit their physical and mathematical relevance,
MalamentHogarth spacetimes cannot be "stable" (in an appropriate
sense) if the strong cosmic censor conjecture in its strongest form is
valid.


The 60minute lecture is followed by a 10minute break. Then
we hold a 3060minute discussion. The language of the presentation is indicated
in the following way:
English
English, except if all participants speak Hungarian
Hungarian
The participants
may comment on the talks and are encouraged to initiate discussion through the
Internet. The comments should be written in the language of the presentation.
The organizer
of the colloquium for the academic year 2003/2004:
Miklós Rédei
(email: redei@hps.elte.hu)



